Statistical mechanics is offering new insights into the structure and dynamics of the Internet, the World Wide Web and other complex interacting systems.

In most complex systems, the nodes vary in their ability to compete for links. Some Web pages, for instance, quickly acquire a large number of links through a mixture of good content and marketing.

Amazingly, such competitive-fitness models appear to have close ties with Bose-Einstein condensation, currently one of the most investigated problems in atomic physics. In an atomic gas, the atoms are distributed among many different energy levels. In a Bose-Einstein condensate, however, all the particles accumulate in the lowest energy ground state of the system and are described by the same quantum wavefunction.